I can't gain weight!

I am very thin, 42kg, 167kg. I am eating a lot because I want to gain some weight, but I can’t. I even tried with some supplements and they didn’t work for me. I look ridicules in everything I wear. I don’t have breast. I am very unhappy! What I can’t gain weight?

Though there may be many reasons why you may be thin, but the most apparent is because of your genetics. If your parents are naturally thin or have a small body frame, then you will most likely have the same small body type, but to some degree your size can also be controlled by your metabolism. If you have a difficult time gaining weight of any kind either fat or muscle then you most likely have a fast metabolism. That means that your body burns calories at a faster than normal rate.